*3.4. Index Quantification, Grading Assignment and Weight Determination*

According to the characteristics of the data, we adopt a variety of methods to quantify, grade and assign the evaluation index, including the classification assignment method and natural breakpoint method. For classified data, such as geological disaster-prone areas and land use types, the corresponding relationship between types and grades is established by using a classification assignment method based on relevant studies, and corresponding scores are assigned. Specifically, geological hazard susceptibility was divided into four grades—none, low, medium and high—and assigned scores of 100, 60, 40, and 20, respectively. The grade of the cultivated land in Jinan city is 6–11, and 6 and 7 are assigned to 100, 8 and 9 to 80, 10 to 60, 11 to 40 and non-cultivated land to 20. Land use types were divided into five grades based on the intensity of human activities in each land use type and assigned values. For numerical data, such as DEM and distance index, the natural breakpoint method is used to divide them into 5 grades with the help of ArcGIS software, and the corresponding scores were assigned. Besides, based on the grading standards of the slope in the grading regulations of agricultural land, slopes were divided into five grades: <2◦, 2◦–6◦, 6◦–15◦, 15◦–25◦ and >25◦.

Common methods for determining the weights include expert scoring, the analytic hierarchy process, the entropy value method and principal component analysis. Of these, the combination of expert scoring and analytic hierarchy process has the advantages of making full use of expert experience and being simple and easy to operate. Therefore, this study adopted the expert scoring method and the analytic hierarchy process to comprehensively determine the weight of evaluation indicators.
